1. Field of the Invention
The present invention relates to a cooling device suitable for cooling component parts in a chassis in an image projection apparatus (liquid crystal projector) or the like in which light modulated by an image display element, such as a liquid crystal panel, is projected onto a projection surface by a projection optical system, thereby displaying an image.
2. Description of the Related Art
In a liquid crystal projector, a lamp for illuminating a liquid crystal panel, the liquid crystal panel which is illuminated by a light beam from the lamp, a power source for driving the lamp, and the like are provided in one chassis.
In order to brighten a projected image, it is desirable to illuminate the liquid crystal panel by using the high-output lamp. However, calorific values of the high-output lamp, the liquid crystal panel which is illuminated by the high-output lamp, the power source for driving the lamp, and the like increases, so that a temperature of each member rises.
Therefore, in order to cool those members enclosed in the chassis, a cooling device is provided for an image projection apparatus.
For example, in the cooling device for cooling the lamp, the lamp is cooled by blowing the wind from a fan to the lamp or by allowing the wind to pass through the lamp by using intake air of the fan.
The air which has cooled the lamp whose temperature becomes very high becomes the high-temperature wind and is exhausted to the outside of the image projection apparatus (outside of the chassis) (refer to U.S. Pat. No. 6,481,854). On the other hand, since the calorific values of the liquid crystal panel, the power source for driving the lamp, and the like are smaller than that of the lamp, the air which has cooled those members becomes the relatively-low-temperature wind and is exhausted to the outside of the chassis.
When the image projection apparatus is used, there is a case where persons who are seated around the image projection apparatus are exposed to the high-temperature wind which has circulated through the lamp. If the persons are exposed to the high-temperature wind, they feel unpleasant. Therefore, in the case of exhausting the wind which has cooled the lamp and the like from the chassis, it is important to properly set exhaust directions of the high-temperature wind and the low-temperature wind.
As a cooling device for cooling the lamp and the power source for driving the lamp, there has been known a construction in which the wind is allowed to flow the circumference of the lamp, the power source, and the like by using a plurality of exhaust fans arranged in parallel in an image projecting direction, thereby exhausting the wind to the outside of the image projection apparatus (Japanese Patent Application Laid-Open No. 2006-235317).
However, in a presentation using the image projection apparatus, a viewer is often seated in the direction of a side surface of the image projection apparatus (direction perpendicular to the image projecting direction). Therefore, according to the projection apparatus disclosed in Japanese Patent Application Laid-Open No. 2006-235317, there is a case where the viewer is exposed to the high-temperature wind from the exhaust fans arranged on the side surface of the image projecting direction.
A construction in which the wind is allowed to flow to the circumference of the lamp and the like by using a plurality of exhaust fans arranged in the direction perpendicular to the image projecting direction, thereby exhausting the wind to the outside of the image projection apparatus has been known (Japanese Patent Application Laid-Open No. 2006-208454). According to the image projection apparatus, a viewer who exists in the direction on the side surface of the image projecting direction is not directly exposed to the high-temperature wind. However, when the high-temperature wind is exhausted in the same direction as the image projecting direction, since the high-temperature wind enters an area where the projection light passes, a fluctuation of the projected image occurs.
A cooling device in which a direction of a wind which cools members such as a lamp and the like are is exhausted can be changed by a duct so that an explainer or a viewer is not directly exposed to a high-temperature wind exhausted from a chassis has been known (Japanese Patent Application Laid-Open No. H09-319007). However, it is necessary to newly provide the duct for changing the direction of the exhaust wind, an external appearance is deteriorated, and a construction increases in size.